Causes

Tight jaw muscles can be caused by a variety of medical conditions and lifestyle habits, such as the following.

Stress and Anxiety

Tight jaw muscles can be a side effect of stress and anxiety. Muscle tension throughout the body increases when you are under a lot of stress or feeling anxious. If you are prone to clenching your jaw, you’ll likely experience tension in your jaw muscles as well.

Temporomandibular Joint Disorders

Conditions that affect your jaw joint are called temporomandibular joint disorders (TMJ or TMD). These conditions are very common, affecting over 10 million Americans.¹ There are three main categories of TMD:

Pain in the muscles that move your jaw
Joint issues involving the cartilage or bone
Arthritis in your jaw joint

Regardless of the underlying cause, all types of TMJ can cause tightness in your jaw muscles.

Teeth Grinding

Bruxism is a condition that occurs when you grind or clench your teeth throughout the day or while you sleep. You might not even be aware of this habit until you develop symptoms. In addition to tight jaw muscles, bruxism can cause:²

Chipped teeth
Sensitive teeth
Locked jaw
Jaw pain
Headaches
Jaw dislocation
Popping in your jaw
Flattened teeth
Grooves in your tongue
Damage to the inside of your cheeks

Tetanus

Tetanus is a condition caused by a bacterial infection from Clostridium tetani, which is common in the outdoors.

This condition is often called lockjaw because tight jaw muscles are one of the most common symptoms of tetanus.³ Other symptoms can include:

Fever
Sweating
Difficulty swallowing
Muscles spasms
Headache
Blood pressure changes
Heart rate changes
Seizures

Tetanus can lead to serious medical conditions, such as pneumonia (an infection of the air sacs in the lungs) or blood clots (collections of blood that form in your veins and arteries).

Are You Overdue for Your Tetanus Booster Shot?

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder. This means that your immune system attacks your joints as if they were foreign to your body. Inflammation causes pain throughout the joints in your body—which can include your jaw joints. Up to 90% of people with RA also have TMJ.⁴

Osteoarthritis

Osteoarthritis (OA) occurs when padding between the bones in a joint wears down over time. Unlike RA, which tends to attack the same joints on both sides of the body at the same time, OA can affect one or more unrelated joints in your body. This means you could have OA on one side of your jaw, but not the other. In addition to tight jaw muscles, other symptoms of OA in the jaw include:⁵⁶

Difficulty opening your mouth
Difficulty moving your jaw to the opposite side
Earache
Headache
Pain when chewing with the affected side
Grinding in the joint

Excessive Chewing

Jaw muscles can become temporarily sore and tight after you’ve chewed gum or sticky candy or eaten tough or fatty food. However, symptoms typically resolve within a few days.